The inside back cover picture showed the liquid‐liquid interface (LLI) self‐assembly structure as a new substrate for analytical sensing. There were two methods to promote self‐assembly at the LLI. On the one hand, strategies for promoting assembly of NPs at the LLI have been developed through the addition of chemical modifiers, promoters, or external voltage. On the other hand, in order to avoid the potential interferences of chemical promoters, shaking organic solution and aqueous solution was proposed as an alternative way to form uniform NPs array at the LLI based on emulsification mechanism. Such strategies to fabricate uniform SERS substrate based on the LLI were demonstrated to be efficient to improve the reproducibility of SERS analysis, which are potentially applicable for practical applications. More details are discussed in the article by Zhang et al. on page 569—580.image